This book presents the results of the global study, Radiation From Nuclear Test Explosions (RADTEST), conducted by the Scientific Committee on Problems of the Environment (SCOPE). Many individuals contributed to the chapters, which include many maps, charts, and tables, as well as reviews of research and extensive bibliographies. The introduction describes the different types of nuclear tests and their locations. It then explores in detail the environmental contamination caused by fallout. Different types of fallout patterns are examined, and case studies are presented. One chapter traces the different pathways leading to the intake of radionuclides from fallout by humans. The book concludes by estimating the doses of radiation that different regions received from fallout and describing health effects that radiation has had on the general population. Some chapters are very technical in nature. The appendix lists all nuclear test explosions as of the publication date, and there is a glossary.